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Superior Millennium Cylinder Complete Assemblies SL36006W-A20P Wide Deck

Select Cylinders:
Single Cylinder4 Cylinder Kit6 Cylinder Kit


Note: Cylinders are not shipped assembled. Rings and piston in separate packaging.

Complete New Millennium Cylinder Assemblies contain the following new parts: head, barrel, valves, valve seats, valve guides, piston, rings, gasket kit, seals, springs, rotocoils, and rocker shafts. The cylinders will not include piston pins or rocker arms.

#1 Aftermarket Cylinder in the World!

With well over 100,000 currently in service around the world and millions of flight hours behind them, Superior’s Millennium Cylinders® are without question, the most popular FAA-approved, PMA aftermarket cylinders in all of general aviation.

But Superior is not just the world’s #1 dedicated cylinder supplier we are also the leader in cylinder design and performance innovation.

Each Millennium Cylinder is an engineering and manufacturing masterpiece. From its advanced computer generated head fin configuration, to its 3-D port contour and increased wall thickness, to its advanced aluminum alloy heads and through hardened AMS 6382 steel barrel, Millennium Cylinder’s deliver performance and quality benefits far surpassing anything else in the air.

Looks great. Performs better.

Put any Millennium Cylinder side-by-side with any other OEM or aftermarket cylinder and the difference in quality, craftsmanship and attention to detail is strikingly obvious.

And while it looks really great, it performs even better. Millennium Cylinders resist cracking, run cooler, last longer and generally out perform the standard cylinders available from Lycoming, Continental or any other aftermarket supplier.

We’re so confident in the Millennium Cylinder’s performance that it’s covered by a full 25-month/TBO* (whichever comes first) warranty. It’s one of the best in the business.
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Features / Benefits

Advanced Aluminum Alloy Heads
Millennium cylinders are manufactured from the most advanced alloys available. That means their structural strength exceeds the latest aerospace industry requirements for air-cooled cylinder heads. In addition, our head castings meet, or exceed, the industry’s more stringent standards for porosity and shrinkage.

Increased Port Wall Thickness
The Millennium cylinder’s unique design also features increased port wall thickness to eliminate problems with premature warpage and cracking. In addition, the exhaust and intake ports are volumetrically matched to maximum output and performance.

Computer-generated Head Fin Configuration
Millennium cylinders feature new and advanced computer-generated head fin configuration that provides more consistent head fin thickness and spacing – that means they deliver more uniform heat transfer and fewer “hot” spots.

Improved Cooling
Millennium cylinders also have aerodynamically smoother surfaces to reduce wind resistance, which enables ambient air to more rapidly draw heat away. Bottom line: Millennium cylinders run cooler and cooler cylinders last longer.

Very high quality casting
Millennium cylinders perform better because they are made better. Our extremely high-quality castings create aerodynamically smoother surfaces to improve overall airflow and cooling.

Through hardened steel barrels
The barrel of each Millennium cylinder offers uniform hardness all the way through the steel walls allowing the barrel to provide even wear while withstanding extreme cylinder temperatures and pressures. This means Millennium cylinders typically reach and often exceed, recommended TBO times.

Ams6382 steel barrels
Millennium cylinders are manufactured with ams6382 steel barrels ensuring complete control of all critical manufacturing processes from the grain size of the steel to the elimination of both micro-impurities and defects in the alloy.

Advanced cylinder barrel choke
Our advanced manufacturing techniques also enable us to craft the Millennium cylinder’s barrel choke from 10 to 13 thousandths of an inch, allowing the rings and pistons to work more efficiently throughout the normal operating temperature range.

Volumetrically matched ports
The intake and exhaust ports on each Millennium cylinder are volumetrically matched for maximum output and performance.


Engine Configurations
AEIO-360 -B1B, -B1D, -B1F, -B1F6, -B1G6, -B1H, -B2F, -B2F6, -B4A, -H1A, -H1B
AEIO-540 -D4A5, -D4B5, -D4C5
HIO-360 -B1A, -B1B, -G1A
HO-360 -B1A, -B1B, -C1A
IO-360 -B1A, -B1B, -B1BD, -B1C, -B1D, -B1E, -B1F, -B1F6, -B2E, -B2F, -B2F6, -B4A, -E1A, -F1A, -L2A, -M1A, -M1B
IO-540 -AA1A5, -AA1B5, -AF1A5, -C1B5, -C1C5, -C2C, -C4A5, -C4B5, -C4B5D, -C4C5, -C4D5, -C4D5D, -D4A5, -D4B5, -D4C5, -N1A5, -T4A5D, -T4B5, -T4B5D, -T4C5D, -V4A5, -V4A5D, -W1A5
LIO-360 -M1A
LO-360 -A1G6D, -A1H6
O-360 -A1A, -A1AD, -A1C, -A1D, -A1F, -A1F6, -A 1F6D, -A1G, -A1G6, -A1G6D, -A1H, -A1H6, -A1J, -A1LD, -A1P, -A2A, -A2D, -A2E, -A2F, -A2G, -A2H, -A3A, -A3AD, -A3D, -A4A, -A4AD, -A4D, -A4G, -A4J, -A4JD, -A4K, -A4M, -A4N, -A4P, -A5AD, -C1A, -C1C, -C1E, -C1F, -C1G, -C2A, -C2B, -C2C, -C2D, -C2E, -C4F, -C4P, -F1A6, -G1A6
O-540 -A4D5, -E4A5, -E4B5, -E4C5, -F1A5, -G1A5 , -G2A5, -H1A5, -H1A5D, -H1B5D, -H2A5, -H2A5D, -H2B5D, -J1B5D, -J1C5D, -J1D5D


Parts per Assembly

  • 2 - Key (MS13997-3)
  • 1 - Cap (MS13998-3)
  • 1 - Elbow (MS20823-8D)
  • 2 - Plug (MS49005-2)
  • 2 - Helicoil (MS9018-05/2-52)
  • 1 - Seat, Valve, Spring (SL10077)
  • 2 - Inner Valve Spring (SL11795)
  • 2 - Spring (SL11800)
  • 1 - Lock Plate (SL12272)
  • 2 - Thrust Button (SL12892)
  • 1 - Seat, Valve Spring (SL13323)
  • 1 - Shaft, Rocker Valve (SL13790A)
  • 1 - Spring (SL14995)
  • 1 - Seat, Valve Spring (SL16475)
  • 2 - Seal - Shroud Tube (SL18661)
  • 1 - Valve, Exhaust (Rotor Type) (SL19001A)
  • 1 - Stud (SL25C-9)
  • 2 - Stud (SL31C-12)
  • 1 - Stud, Assembly (SL36006W-A1)
  • 2 - Key, Valve (SL60009)
  • 1 - Valve, Cover (SL61247)
  • 1 - Guide, Intake (SL61681A)
  • 1 - Spring Seat (SL654441)
  • 4 - Bushing (SL66610)
  • 2 - O-Ring (SL70310)
  • 1 - Ring, Oil Seal, 4.84 Id X .04 (SL71481)
  • 1 - Gasket (SL71973)
  • 1 - Seat, Intake (SL72057A)
  • 1 - Seat, Exhaust (SL72058A)
  • 1 - Ring, Oil Control (SL73857A)
  • 1 - Valve, Int. (SL73938)
  • 1 - Guide, Exhaust (SL74230A)
  • 2 - Ring, Piston (SL74241A)
  • 1 - Piston (SL75089A)
  • 1 - Gasket (SL75906)
  • 1 - Gasket (SL77611)
  • 2 - Helicoil (SL-STD-1872)
  • 6 - Screw (STD-1925)
  • Frequently Purchased With
  • Customers Also Viewed


Curt H Verified Purchase


June 19, 2021

Great Product, good price , fast shipping

Burt S
April 20, 2021

Great quality but I wish they would go ahead and size the rings and install the piston, like they used to do. Would also be nice to be able to request a specific piston weight to better match what was removed from the engine or the opposite cylinder piston. I ended up using my old piston in the new cylinder to avoid a 20+ gram mismatch.

Volo A
February 22, 2018


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Do these come Millenium Cylinders come assembled?

Per Superior: Our cylinders are assembled into a valve assembly and the customer has to fit the rings to the piston and piston to the cylinder.

Q: Does Millennium cylinder assembly SL36006W-A20P, your part number 08-11749, come with the piston and ring?

Yes, this will come with the piston and ring.

Q: Are the Superior Millenium Cylinders interchangeable with the Lycoming cylinders?

Yes, they are interchangeable. This model is for engine models: O-360-A, C, F, G; IO-360-B, E, M; HO-360-C; HIO-360-B; LO-360-A; AEIO-360-B, H; O-540-A, E, G, H; IO-540-C, D, N, T; AEIO-540-D (Wide Deck).

Q: Are the Superior Millenium Cylinders #08-11749 interchangeable with Lycoming cylinders of O-360-A1AD serial #L-28803-36A?

Per Superior: Yes. It is eligible and interchangeable with O-360-A1AD.

PMA No. PQ0060SW Supplement No. 1 Eligibility SL36006W-A20P Revision No. A Page 2 of 3 PART NAME PART NUMBER REPLACEMENT FOR APPROVAL BASIS AND APPROVED DESIGN DATA ELIGIBILITY (MAKE) ELIGIBILITY (MODEL) IO-360-B1E IO-360-B1F IO-360-B1F6 IO-360-B1G6 IO-360-B2E IO-360-B2F IO-360-B2F6 IO-360-B4A IO-360-L2A LO-360-A1G6D LO-360-A1H6 O-360-A1A O-360-A1AD O-360-A4P O-360-A1P O-360-C4F O-360-C4P O-360-A1D O-360-A1F O-360-A1F6 O-360-A1F6D O-360-A1G O-360-A1G6 O-360-A1G6D

Q: Does the Superior cylinder SL36006W-A20P, come with piston pin and plugs?

No, you will also need the SL13444-1 (our part # 08-11595) which is the pin & plug assembly

Q: Will this cylinder come with the necessary paperwork so my AP mechanic can legally install it in my certified airplane?

This unit is FAA PMA'd for install on certificated aircraft. Copies of the PMA are available on Superior's website.

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